Fireplace heater



Nov. 28, 1939. H. w. MAURER 2,181,

FIREPLACE HEATER Filed Sept. 18, 1956 6 Sheets-Sheet l F-lG'l INVENTOR. Herman W Maurer BY M +@c ATTORNEY.)

Nov. 28., 1939. H w, MAURER 2,181,624

FIREPLACE HEATER Filed Sept. 18, 1956 6 Sheets-Sheet 2 FIG 2.

INVENTOR. Herman W. Maur'er' ATTORNEYS Nov. 28, 1939. H, w, MAURER 2,181,624

FIREPLACE HEATER Filed Sept. 18, 1956 6 Sheets-Sheet 3 I0 I INVENTOR I9 H HermanW Maurer 65 BY ELM kfiza 607 64 ATTORNEYS Nov. 28, 1939. H. w. MAURER FIREPLACE HEATER Filed Sept. 18, 1936 6 Sheets-Sheet 4 INVENTOR.

He rman W- Maurer gum '4 /[C.

49 F-lG 9 ATTORNEYS.

Nov. 28, 1939. H. w, R R 2.181,624

FIREPLACE HEATER Filed Sept. 18, 1936 6 Sheets-Sheet 5 INVENTOR. Herm om-W- Maurer BY M q ATTORNEYS Nov. 28, 1939. H. w. MAURER 2,181,

' FIREPLACE HEATER Filed Sept. 18, 1 956 6 Sheets-Sheet 6 I l 1 l l 1 INVENTOR. Herman W-Mcmurer BY (g y-aw? 7 ATTORNEYS Patented Nov. 28, 1939 UNITED STATES PATENT OFFICE 54 Claims.

This invention relates to fireplace heaters and particularly to such heaters in which provision is made for circulation of air through a heating chamber to supply heated air to a building.

An object of this invention is to provide such a heater which will simultaneously radiate heat into the room in which it is located and at the same time serve as an air heater having a large area for warming air to be circulated in the building.

Another object is to provide a device of this character in which the burning of fuel may be regulated so as to increase or decrease the proportion of heat radiated into a room from the fireplace relative to the amount of heat carried from the heater by the air circulated through the building and the air heating chamber of the heater.

Another object is to provide a fireplace heater having a fuel hopper such that it will be unnecessary to add fuel to the unit through the open portion of the fireplace.

Another object is to provide a heater which may be positioned in a partition or wall of a building with a fireplace opening into a room on one side of the partition to heat such room and the remainder of the heater positioned in a service room on the opposite side of the partition and arranged so that substantially allfuel and ash handling may be done in the service room, and hot air ducts leading to other rooms in the building from the heater may be located in the service room.

A further object is to provide a compact selfcontained unit to circulate clean, warmed, hu midified air in a building from the space usually occupied by a fireplace.

A further object is to concentrate fire tending, so that in tending a fireplace, the whole house may be heated, thus making the usual enjoyable fire tending replace the work of furnace fire tending.

Still a further object is to provide in a fireplace using fuels which usually give off excessive smoke, a more complete burning of volatiles to minimize smoke and to provide in a front combustion chamber a clean blue flame.

Another object is to provide a combined furnace and fireplace which may be installed as a unit and which is simple in construction, inexpensive to manufacture, and adaptable for installation without a special type chimney, and which occupies only a space in a wall instead of a special room.

Further objects and advantages of the invention will be apparent from the following detailed description made in connection with the accompanying drawings, in which;

Figure 1 is a perspective view with parts broken away of a heater embodying my invention; a Fig. 2 is a front elevational view of a fireplace heater embodying my invention;

Fig. 3 is a sectional view on the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary detail view in section 10 showing a modified method of connecting the fireplace heater to a chimney fiue;

Fig. 5 is a view similar to Fig. 3 showing another modification;

Fig. 6 is a fragmentary detail view in section 15 showing a modified method of connecting a fireplace heater into a horizontal fiue opening;

Fig. 7 is a side elevational view of the heater with the casing removed and with parts broken away;

Fig. 8 is a rear elevational view, with casing removed and partly in section and with parts broken away, of the fireplace heater using a horizontal flue pipe to carry off the burned gases;

Fig. 9 is a top plan view of the fireplace heater 2,5 illustrated in Fig. 8, positioned against a wall of a building;

Fig. 10 is a front elevational view of the fireplace heater shown in Fig. 2. with the casing removed;

Fig. 11 is a side elevational view of the structure shown in Fig.10;

Fig. 12 is a section on the line l2-l'2 of Fig. 10;

Fig. 13 is a detail in section of the upper portion of the fuel hopper;

Fig. 14 is a fragmentary detail front view of the heater partly in section and with parts broken away, showing the construction of the fire screen and fire shield;

Fig. 15 is a section on line l5-l5 of Fig. 14; o and Fig. 16 is a section on the line IB-IB of Fig. 14.

According to my invention the fuel is burned in a slidable grate or basket I carried on supports 18 which are shown as angle irons secured to 45 side walls 6 of the heater by any suitable means, such as welding. It is to be noted that the rear of the grate is open and the bottom is arranged to slide underneath a fuel pan ll located in the rear of the heater. Thus, by sliding the grate l 60 on its supports 18 to the rear of the heater the effective grate area is decreased and by sliding the grate forward on its supports the effective grate area may be increased. Continued sliding forward of the grate withdraws the rear end of 66 the bottom of the grate from under the fuel pan 17, so that the ashes and clinkers may be readily dropped into an ashpan positioned underneath the grate and fuel pan and arranged to be withdrawn from the front or rear of the heater, as will be hereinafter pointed out. It is to be understood that the supports 18 are of sumcient width so that the tapered form of the grate does not cause the grate to slide ofi the supports during normal forward or backward movement of the grate. I

The space above the grate and fuel pan is divided into a front or open combustion chamber 2 and a rear or closed combustion chamber 3 by an air-cooled partition 4. The air-cooled partition extends across the entire width of the combustion chamber of the fireplace heater and has a closed bottom 5 which terminates just above the level of the upper edge of the front portion of the grate I, so that in normal operation of the heater the bottom 5 of the partition will be positioned just above the fuel bed.

The side walls 6 of the heater, which form the sides of the front and rear combustion chambers, are constructed of any suitable heat-resistant and heat-conducting material; such as sheet iron, and the front and rear walls of partition 4 may also be constructed of the same material. Rear wall 19 of the combustion chamber 3 may be similarly constructed and is seen to be an extension of the rear wall of the fuel pan 11. It is to be noted that the air-cooled partition 4 is inclined upwardly and forwardly from the rear portion of the front combustion chamber and the bottom 5 is positioned above the forward edge of the fuel pan 11. In this manner the fuel resting on the fuel pan-11 does not burn as readily as the fuel in the grate I, so that during operation of the heater the tendency is for the portion of the fuel on the grate to burn quite vigorously, with part of the resulting hot gases passing over the portion of the fuel on the fuel pan TI. The hot gases are thus effective in driving off the volatile combustible material in the fuel on the fuel pan 4. This volatile material may be carried into the rear combustion chamber 3 with a quantity of air which flows through the front combustion chamber and under the bottom of the partition 4 and which is thus preheated in passing over the fuel bed on the grate i to facilitate efficient combustion in the rear chamber 3. In this connection it is to be noted that the rear combustion chamber 3 gradually increases in cross-section from its upper and lower extremities toward the center, so as to provide a relatively large central chamber to facilitate the thorough and efiicient combustion of the fuel and a large surface area for heating air circulated around the walls of the rear combustion chamber, as will be later described.

The gases from the fuel burning in the grate beneath the front combustion chamber 2 pass upwardly through said chamber and heat the side walls 6 of the heater and front wall 1 of the aircooled partition 4. From the front chamber the gases pass into a converging smoke hood 8 which leads to an outlet flue or chimney 32. The hot gases in the rear combustion chamber 3 heat the side walls 6 and rear wall 19 of the heater, and rear wall of the air-cooled partition 4, and rise into a radiator Ill which encircles the smoke hood 8. The radiator has an opening ll thereinto opposite the point at which the gases from the rear combustion chamber enter the radiator. Thus, the products of combuschambers in which air from combustion tion from the rear chamber are carried up into the radiator, around which they circulate and pass into the smoke hood 8 and out the flue 32, along with the gases from the front combustion chamber 2.

Above the air-cooled partition 4 and in the smoke hood 8 is a smoke shelf 30. A similar shelf 3i is located adjacent the lower edge of the opening ll through which the gases from the radiator enter the smoke hood 8. The purpose of the smoke shelf is to promote an efncient and uniform flow of the gases from the respective combustion chambers out through the flue 32 and to minimize the possibility of a down draft from the chimney, causing the products of combustion to back up into the combustion chambers and the room in which the heater may be located.

A suitable shell or casing l2, which may be made of sheet metal with welded or slip joints, surrounds the combustion chambers, except for the open portion of the front combustion chamber, and thus provides an i3 between the casing and walls of the combustion the building may be circulated and heated, as will be hereinafter pointed out.

As previously mentioned, the air-cooled partition 4 extends entirely across the front combustion chamber 2 and both ends open into the air heating chamber l3. In order to promote the circulation of air through the chamber 4, bottom duct l4 and top duct I5 are provided. Bottom duct I4 is centrally positioned in the air-cooled partition 4 and communicates with the rear portion of the air-heating chamber i 3 through the rear wall 19 of the heater. Top duct l5 may be similarly positioned in the central portion of the air-cooled partition 4 and communicates with the air-heating chamber I 3 through upper front wall 9 of the smoke hood 8. Thus, the space over the fuel pan 11 is divided into two portions adjacent the bottom of the air-cooled partition 4, so that a plentiful supply of air may be circulated through air chambers around the burning fuel to efiiciently and rapidly heat the air and minimize the danger of damaging the partition and duct by excessive temperatures. The chamber in the air-cooled partition 4 also communicates with the air-heating chamber l3 through a vertical passage l6 which is adjacent and partially surrounds the smoke hood 8 and is surrounded by the radiator I0, so that the air entering the air-heating chamber l3 through the passage I6 is in intimate contact with the smoke hood 8 and radiator Positioned on each side of the rear combustion chamber 3 are fuel hoppers or stokers 43 each of which communicates with the fuel space over the pan 11 through an opening 44. The fuel hoppers are arranged so that fuel therein will fall by gravity and be fed to the fuel pan, so that it may be raked onto the grate as required. A vertically sliding door 45, preferably constructed of sheet iron or other heat-resistant material, is arranged to normally close the opening 44 and an enclosed slideway 38 is provided above the opening 44 to receive the door 45, which may be raised by a poker or other implement when it is desired to admit fuel from the hopper 43 to the fuel pan 11. It will be seen that the fuel immediately in front of the opening 44 rests on the bottom of the pan 11, so that combustion is discouraged at that point since there is inconsiderable circulation of air through that portion of the fuel. As the fuel moves onto the grate, air is admitted to the fuel,

air-heating chamber ill, to be effectively heated thereby.-

which burns and heats the adjacent fuel on the pan 11, so that the volatile combustible material may be driven off to mix with hot air passing over the burning fuel on the grate l and rise into the rear combustion chamber 3, where the volatile combustible material may burn as mentioned above. Thus the temperature adjacent the openings 44 is maintained relatively low, so that the possibility of the fuel in the hoppers 43 becoming ignited is minimized. In the even that fuel in the openings 44 ignites, the weight of the sliding door 45 forces the door through the burning fuel and shuts off the air supply so that combustion in the fuel hoppers is suppressed.

Hopper type charging doors 41, provided with radial side walls 46, are arranged in the top of the fuel hoppers 43 for the introduction of fuel to the hoppers. These doors may be positioned in the side panels of the shell or casing l2, as shown in Figs. 1, 8, 9, 10, 11 and 12, so that fuel may be introduced to the hoppers from the same room in which the heater is located, or the doors may be positioned in the rear panel of the casing, as shown in Figs. 8 and 9, so that fuel may be added to the hoppers from the rear or a room on the other side of a wall or partition in which the heater may be located. The radial side walls 46 serve as a receiving hopper when the charging door is open, to facilitate the charging of the fuel hoppers.

As will be seen in Figs. 3, 10 and 11, a tubular passage or opening 61 is positioned in the upper portion of the fuel hopper andcommunicates with the radiator I0. In the event that smoke or gas should, for any reason, accumulate in the fuel hoppers it may be released through this opening to prevent its introduction into the room in which the charging door d'i of the hopper opens. Also, the opening 57, being positioned adjacent the lowermost portion of the radiator It, facilitates the introduction of a suitable cleaning tool in the radiator to remove soot and the like. A suitable closure or door 43 may be provided for the opening iii.

The door 48 is hinged at the top and by suitable means such as gravity is arranged to normally hang open when the charging door ll to the hopper 43 is open. A bar or rod 39 extends be tween the radial side walls it of the door M and is arranged to engage the door '38 to hold it shut when the charging door #3? is closed.

Extending through the air-heating chamber l3 in the rear of the heater and communicating with the rear combustion chamber 3 is a passage 22 provided with a door 23 located in the rear panel of the casing l2. This passage may be used to introduce cleaning tools into the rear combustion chamber and gives ready access to the interior of the heater. Furthermore, in the event that under certain conditions it may be desirable to dispense with the use of the fuel hoppers described above, it is contemplated to add fuel to the heater through the passage 22.

Underneath the grate I and fuel pan ll is an ashpit 24 which may be open at either the front or rear, or both, as desired, in order to admit air to the burning fuel and to adapt the manner of removing ashes to the particular type of heater installation contemplated. As shown in Fig. 3 it is open at the front and rear, so that the ashpan 25 may be withdrawn from either end for disposal of the ashes. It is to be understood, however, that the ashpit is closed off from the airheating chamber l3, so that there is no danger of ash dust commingling with the air circulating through the air-heating chamber.

In an installation such as that shown in Figs. 8 and 9, in which the heater is positioned adjacent a wall, which could be an outside wall of a building, and adjacent a chimney 34, it is seen that one of the charging doors 41 may be conveniently arranged to open into a room in which the heater is located and the other charging door arranged to open through the wall 48. In this manner the heater may be fueled from within or without the building.

Also, an ash door 49 may be arranged in the wall 48 to the rear of the ashpit 24, so that the ashpan 25 may be conveniently removed for disposal of the ashes without its being handled in the room in which the heater is located.

In adapting a fireplace heater constructed according to the present invention to various installations it may be desirable to position the heater in a building so that it is more or less remote from the chimney through which the gaseous products of combustion are to be carried off. In Figures 1, 2 and 3, the flue 32 is shown as extending away from the opening in the top of the smoke hood 8 in a substantially horizontal direction and leading to a chimney, not shown. Air which has been heated by circulation through the air heating chamber l3 may be introduced directly into the room in which the heater is located through openings 33 in top panel 28 of the casing 12 of the heater. If desired, this hot air may be carried off through openings 33 and suitable hot air ducts or leaders 36 to other rooms in the building, in which case the heater serves as a central heating plant for the building.

In Fig. 4 I have shown a modified method of installation in which the heater is positioned directly under a brick chimney 34 and the smoke hood 8 leads directly to the flue in the chimney. Hot air from the air-heating chamber l3 enters leaders 36 positioned alongside the chimney 3 t through openings 33. The leaders 36 may conduct the heated air from the chamber l3 to other rooms in the building, as desired.

Fig. illustrates an installation similar to that of Fig. i, except that in this case a vertical sheet metal chimney 31, which may be enameled to increase its elhciency, is used instead of the briclr chimney 3d. The hot air leaders or ducts are arranged to completely enclose the sheet metal chimney so that the air passing through the leaders will be maintained at an elevated temperature by contact with the sheet metal chimney 37 which is heated by the hot gases from the combustion chamber. In this installation, as well as that illustrated in Fig. 4, the leaders 36 may carry the hot air to rooms in the building other than that in which the heater is positioned.

In Fig. 6 is illustrated a method of installation in which the heater projects into the room and is positioned flush against a wall 35 in front of a chimney built into the wall. The gaseous products of combustion are carried ofi horizontally from the smoke hood 8 through a short horizontal flue 40 positioned immediately above the radiator l0 and below the top panel 28 of the casing 12. In this installation the manner of carrying off the gases from the combustion chamber is hidden and, for this reason, may be preferred when it is believed that the heater will present a more pleasing appearance if the outleading flue is not shown. Furthermore, such a method of installation presents a broad top to the heater which may form a more desirable mantle 10 described. The fire screen is retained in any desired withdrawn or retracted position relative to the pocket by means of any suitable mechanism, such as a device known to the trade as a unique sash balance and indicated by the numeral 62.

The fire shield comprises a front panel 55 and a rear panel 56 disposed on either side of the fire screen and joined together at the top edges by cross member 51. The ends of the panels 55 and 56 are held in spaced relation by members 58 positioned parallel to and a short distance inwardly from the edges of the panels to form U-shaped channels 62. The combination fire screen and fire shield is carried in a decorative arch formed in part by angle members 54 which are positioned at the sides of the opening in the front combustion chamber 2 and secured to the front of the casing l2 in any suitable manner, such as by stove bolts 62. The fire shield adjustably carrying the fire screen in the pocket between the 39 panels 55 and 56 is in turn adjustably carried by the angle members 54 by any suitable means, such as the "unique sash balance 52 mentioned above. The angles 54 extend above the opening to the front combustion chamber 2 and are connected by cross members 59, one cross member being positioned adjacent the top of the opening into the front combustion chamber and the other cross member extending between the top ends of the side angles 54. A decorative panel 60 carried between such extended portions of the angles and the cross members 59 forms with a panel 6| an enclosed recess or pocket which is arranged to receive the fire screen and fire shield when in elevated position. Thus, the combined fire screen and fire shield may be pushed up into the recess behind the decorative panel 60 leaving the opening to the front combustion chamber unobstructed to permit access to the grate and combustion chamber. If it is desired to screen off the fire the fire screen alone may be drawn down and out of the pocket in the fire shield into the opening to the combustion chamber; If it is desired to close off the front combustion chamber entirely, such as when the heater is not in operation, or if it is desired to heat the building solely by the air passing through the heating chamber l3, the fire shield may be drawn down to a position even with the top of the grate. In this manner the heat radiated to the room in which the heater is positioned may be effectively controlled and the supply of air for combustion in order to control the temperature of the fire may be conveniently regulated. It is to be observed that the fire screen and fire shield may be arranged to partially close the opening into the front combustion chamber so that a suitable degree of control of the combustion and radiant heat may be obtained. The draft on the fuel may be regulated by raising and lowering the fire shield so that a proper rate of combustion may be secured. Lowering the shield to the upper edge of the grate closes off the upper portion of the opening into the front combustion chamber 6 so that all the air entering the combustion chambers must pass up through the fuel in the grate I, thus affording a simple and effective manner of controlling the draft through the bed of fuel. Raising the fire shield permits more air to enter the combustion chambers over the top of the fuel, thus decreasing the proportion of the air flowing through the fuel bed; lowering the fire shield so that its lower edge is below the grate has a throttling effect on the fiow of air, so that the rate of combustion may be thus checked. It is to be observed that,

with the fire shield in a lowered position, the I heat radiated from the front combustion chamber is diminished. Furthermore, when in a partially lowered position, the fire shield is effective in preventing smoke escaping from the front combustion chamber into the room, such as when a fire is being started or the draft is insufllcient.

A further control of the fiow of gases through the heater is provided by a damper I! which may be positioned adjacent the opening from the smoke hood 8 to the outlet l8. The efiective size of the passage through which the gases fiow may be thus altered by the position of the damper which is actuated by a notched rod l9 extending downwardly through the smoke hood 8 and into the upper portion of the front combustion chamber 2. The damper is held in adjusted position by a suitable fiange 2| secured to the wall of the front combustion chamber 2 and arranged to engage one of the notches 20 in the rod l9 so as to hold the damper I! in any desired open or closed position.

When the heater is in operation the metal walls of the combustion chambers are heated by the burning fuel and heat the air in the air heating chamber l3 which rises and is carried through the above mentioned hot air ducts or leaders 36 or may be introduced directly to the room in which the heater is located through the grills 4|.

The flow of air through the air heating chamber I3 is facilitated and the heating of such air and the cooling of the walls of the combustion chambers is aided by convection plates 63. These plates are positioned in the heating chamber I 3 in spaced relation with the walls of the combustion chambers so as to provide a plurality of air passages 64 between'the convection plates 63 and the walls of the combustion chambers. It is preferable that the convection plates to be supported so that the air passages 64 are open around all edges of the plates, so that the air a may eddy and fiow around these plates to promote a better flow of the air and to facilitate the heating. This may be accomplished by carrying the convection plates on supports 65 secured to the walls of the combustion chambers in any suitable manner, such as by welding.

Where a wall of the combustion chamber is of considerable expanse, such as the rear wall 19, it is preferable that a plurality of convection plates be employed to produce a more desirable flow of air through the heating chamber l3. In this case it is preferable that the top of each plate be positioned closer to the wall of the combustion chamber than the bottom, so that the space between the convection plate and the heated metal wall of the combustion chamber progressively decreases towards the top of the plate. Also, the top of each plate may extend a short distance into the space between the next higher convection plate and the wall of the combustion chamber, so that each convection plate overlaps the next lower plate and is, in turn, overlapped by the next higher plate, as shown in Figs. 3, 7 and 8.

In operation the burning fuel heats the walls of the combustion chambers which radiate heat through the air heating chamber l3 to the convection plates 63, which absorb this radiant heat and in turn radiate heat through the air heating chamber. Air 13 positioned between a convection plate and hot wall of a combustion chamher is rapidly heated and tends to rise more rapidly than air C positioned between the convection plate and casing l2. This rapid rise of the air B tends to draw in the air around the bottom and ends of the convention plate, which air is also rapidly heated and carried upwards. Thus a circulation of the air in the heating chamber 53 is induced which promotes a turbulent flow therein, drawing the relatively cool air C from adjacent the casing l2 into the space between the convection plates and the hot walls of the combustion chambers, so that the flow of air immediately adjacent the walls of the combustion chamber is accelerated and maintained at a higher velocity than in other portions of the heating chamber l3. By thus providing a plurality of plates open around all margins a general flow of air towards the hot walls of the combustion chambers is promoted so that at a plurality of points the air is drawn away from the outer casing 52 and circulated in intimate relation with the hot walls or the combustion chambers so as to maintain the casing l2 relatively cool and to efiiciently heat the air circulated through the chamber l3. The circula-- tion of air through the air heating chamber 33, air cooled partition 4, and the various other ducts and passages is illustrated in the drawings by means of the wavy bodied arrows. The arrows having straight bodies indicate the flow of air for combustion and the gaseous products of combustion through the ash pit, combustion chambers, smoke hood, and various dues and passages.

In the event that the air heating chamber 43 is of considerable depth, or that the adjacent walls of the combustion chamber are particularly hot, it may be desirable to position convection plates 66 behind the convection plates previously mentioned. These secondary convection plates have a cumulative efiect on the free circulation of air through the first mentioned convection plates, being heated by radiant heat from the first convection plates and in turn radiating heat into other portions of the chamber 3. The convection plates, one above another and in overlapped relation apparently have the effect of a plurality of vanes which direct the cooler air C towards the hot walls of the combustion chambers where it is heated and becomes the hot air B which rises and is carried out the openings ill in the top of the heater.

The air circulated through the air heating chamber l3 may be humidified by means of evaporator pans 26 which are suspended from the top panel 28 of shell l2 by means of bolts 2'1. These pans are preferably positioned on each side of the smoke hood 8 and above the radiator Ill. As will be seen in Figs. 3, 8 and 10 and 11, the evaporator pans are made to fit closely to the upper surface of the radiator ill, thus maintaining the water in the pans at an elevated temperature to facilitate evaporation. A pipe 29 connects the pans 26 so that the water in each is maintained at the same level. Water may be added to the pans through the openings 4| in the top panel 28 or may be supplied automatically through the pipe 14 connected to a suitable source and controlled by any well known means, such as a fioat valve (not shown).

A pipe 15 also connected to a suitable source of supply may, be arranged to drip water into the ash pan 25 in order to keep the ashes in a moist condition. The control of the dripping may be effectuated by a thermostatic valve indicated at 16 which is arranged to open and admit water to the ash pan when the temperature in the ash pit 24 is above a predetermined point.

In Fig. 11 is shown an arrangement of coils 13 which encircle the opening 44 through which the fuel from the hoppers 43 enters the combustion chambers. These water coils may be connected with a hot water tank in a well known manner to provide a supply of hot water for use in a building. In addition, it is to be noted that the effect of the coils will be to maintain a moderate temperature around the opening 44, so that the fuel therein and in the bottom portion of the hopper 43 will be less likely to ignite or fume.

The operation of the heater is considerably improved by the use of blowers or fans 68, which may be conveniently arranged in that portion of the air heating chamber 13 positioned adjacent the sides of the combustion chambers. The fans draw in relatively cool air from around the bottom of the heater and force it through the heating chamber l3 and out through the openings 33 and H. In this manner considerably greater quantities of air may be heated than when the circulation of the air is merely induced by convection currents in the heating chamber caused by the tendency of the hot air to rise.

It will be apparent that the bottom edge 5 of the air cooled partition l positioned just above the burning fuel will be heated much more than other portions of the walls of the combustion chambers. As pointed out above, it is desirable to promote the circulation of air through this portion of the air cooled partition. Such circulation may be greatly increased, especially when the blowers 38 are employed, if air hoods 69 are positioned in the air heating chamber i3 and inclined upwardly and rearwardly so that their upper edges are just above the bottom edge 5 of the air cooled partition. These air hoods are arranged to direct the flow of air into the sides of the air cooled partition 4 and between the sides of the combustion chambers and the fuel hoppers, thus facilitating the cooling of these parts of the heater. I

Legs 10 support the heater above the floor level so that the air heating chamber l3 may be open about the bottom. This opening may be provided with filters M which may be of any well known construction and which are arranged to filter air entering the air heating chamber It.

A hearth II is provided for the front of the fireplace. It may be constructed of any suitable material such as concrete, steel, marble or stone, with a suitable heat insulating material between the hearth and floor. When using such a hearth the air enters the air heating chamber l3 at the bottom of the sides of the heater between the legs 10, as shown in Figure 1.

In some installations it may be desirable that an ornamental base be extended entirely around the bottom of the heater. In such case there would be no openings around the bottom of the heater to permit cool air to enter the air heating chamber l3, so it is contemplated to provide a cold air duct 83, illustrated in Fig. 8, in the floor underneath the heater. Such a cold air duct may lead to a cold air intake, opening to the air outside the building so as to draw fresh air into the building or, as illustrated, it may open into a room below that in which the heater is located. Thus the heater may be positioned in a room on the first floor of a building and a cold air duct 83 communicate with the basement or cellar of the building, so that air from the cellar will be drawn up through the air heating chamber 13.

An installation which combines blowers or fans 68, filters BI, and a cold air duct 83 leading into the cellar, affords a simple and effective air con- 10 ditioning unit. In cold weather, the heater will function to draw the cold air out of the cellar and filter and heat it, and circulate it as warm air through the building. In warm weather, the cool airfrom the cellar, which hence may be relatively low in humidity, may be drawn up through the duct 83 by the blowers 68, filtered and circulated through the upper rooms of the building.

Of course in this latter case no fuel would be burned in the combustion chambers; merely the 2 cool air from the cellar would be circulated.

It will thus be seen that I have provided a fireplace heater simple in design and inexpensive to construct and which lends itself to various modifications for installation in buildings of different design. Also, provision is made for conditioning the circulating air, such as filtering and humidifying, and a construction is provided by which the same unit may be used to heat a building incold weather and circulate cool air from the cellar in so warm weather. Furthermore, a heater constructed according to the present invention may be assembled as a unit for any installation desired, so that in remodeling the change may be made with a minimum of construction and alter- 5 ation on the premises.

It is to be understood that, although but a few modifications of my invention have been shown and described, numerous alterations of my invention are contemplated and may be made without departing from my invention and intended to be included within the scope of the appended claims.

What I claim is:

1. A fuel burner for heating a building comprising a grate, a front combustion chamber having an opening into a room in the building, a rear combustion chamber, an air heating chamber enclosing said rear chamber and a portion of the front heating chamber, and including a hollow partition separating said chambers, and means for carrying off the products of combustion, said last named means including a flue communicating with an upper portion of the front combustion chamber and a heat radiator encircling said flue, said heat radiator communicating with the rear combustion chamber and the flue and positioned within the air heating chamber whereby hot gases from the rear combustion chamber are passed through said radiator and out the flue and said radiator heats the air in the air heating g0 chamber.

2. A fuel burner for heating a building comprising a grate, a front combustion chamber having an opening into a room in the building, a rear combustion chamber, an air heating chamber 35 enclosing said rear chamber and a portion of the front heating chamber, and including a. hollow partition separating said chambers, a firing door communicating with the rear combustion chamber to admit fuel to the grate otherwise than 7 through the front combustion chamber, and

means for carrying off the products of combustion, including a flue communicating with an upper portion of the front combustion chamber and a heat radiator encircling said flue, said heat radiator communicating with the rear combus- 1 tion chamber and the fiue and positioned within the air heating chamber whereby hot gases from the rear combustion chamber are passed through said radiator and out the flue and said radiator heats the air in the air heating chamber. 5

3. A fuel burner for heating a building comprising a grate, a front combustion chamber having an opening into a room in the building, a rear combustion chamber, an air heating chamber enclosing said rear chamber and a portion of the u front heating chamber, and including a hollow partition separating said chambers, said rear combustion chamber having its greatest horizontal cross-sectional area at a point intermediate the top and bottom of said chamber, and means 13 for carrying off the products of combustion.

4. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heating chamber around the rear combustion chamber and a portion of the front combustion chamber,

a second air heating chamber continuous with the first air heating chamber and disposed between the front and rear combustion chambers, means for admitting relatively cool air from the building into the air heating chamber adjacent the bottom thereof, means for withdrawing relatively warm air from the top of the air heating chamber for circulation in the building, and means for carrying off the gaseous products of combustion from the combustion chambers.

5. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heating chamber around the rear combustion chamber I and a portion of the front combustion chamber, a second air heating chamber continuous with the first air heating chamber and disposed between the front and rear combustion chambers, the rear combustion chamber having an opening 40 at the bottom communicating under the second air heating chamber with the front combustion chamber, said rear combustion chamber increasing in effective cross-sectional area above said opening to provide an enclosed combustion space 45 of increased volume, and means for carrying of! the gaseous products of combustion from the combustion chambers.

6. A fuel burner for heating a building comprising a grate, a front open combustion cham- '50 ber, a rear combustion chamber, an air heating chamber around the rear combustion chamber and a portion of the front combustion chamber,

a second air heating chamber continuous with the first air heating chamber and disposed be- 66 tween the front and rear combustion chambers, the front wall of the air heating chamber being inclined toward the front of the burner to overlie the front combustion chamber and the rear wall of the air heating chamber being inclined away m from the opposite wall of the rear combustion chamber to provide a progressive increase in effective cross-sectional area of the rear combustion chamber. and means for carrying off the gaseous products of combustion from the combustion chambers.

7. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heating 7o chamber between the front and rear combustion chambers, an annular heat radiating flue above and in communication with one of the combustion chambers and a common outlet flue for carrying oil. the gaseous products of combustion 75 from the other of said combustion chambers and the annular flue.

8. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heating chamber between the front and rear combustion chambers, an annular heat radiating flue above and in communication with one of the combustion chambers, the other of said combustion chambers extending upwardly within the annular flue, and a common outlet flue for carrying off the gaseous products of combustion from the annular flue and said other combustion chamher.

9. A fuel burner for heating a building com prising a grate, a front open combustion chamber, a rear combustion chamber, an air heating chamber between the front and rear combustion chambers, an annular heat radiating flue above and in communication with one of the combustion chambers, the other of said combustion chambers extending upwardly within the annular flue, said upwardly extending portion being in communication with the annular flue to receive combustion products therefrom, and an outlet flue continuous with said upwardly extending portion for carrying off the gaseous products of combustion.

10. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heatin chamber between the front and rear combustion chambers, an annular heat radiating flue above one of the combustion chambers and having an inlet opening in communication therewith, an outlet flue continuous with the other of the combustion chambers and communicating with the annular flue through an opening in the latter and arranged to carry off the gaseous products of combustion, and the said opening in the annular flue being opposite the inlet thereof whereby hot gases entering the annular flue are divided to flow through separate courses and are then commingled in leaving the burner.

11. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heating chamber between the front and rear combustion chambers, an annular heat radiating flue above one of the combustion chambers and having an inlet opening in communication therewith, an outlet flue continuous with the other of the combustion chambers and communicating with the annular flue through an opening in the latter and arranged to carry off the gaseous products of combustion, the said opening in the annular flue being opposite the inlet thereof, and the annular flue inclined upwardly from the inlet to the opening into the outlet flue whereby hot gases enter the annular flue and flow through separate courses in a generally ascending direction to the outlet.

12. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heating chamber between the front and rear combustion chambers, an annular heat radiating flue above and in communication with one of the combustion chambers, the other of said combustion chambers extending upwardly beyond the annular flue, an opening in the annular radiator continuous with said upwardly extending combustion chamber portion, a shelf projecting from the edge of said opening to deflect gaseous products of combustion rising through said upwardly extending portion away from the opening, and an outlet flue for carrying the gaseous products of combustion from the upwardly extending portion and the; annular radiator.

13. A fuel burner for heating a building comprising a grate, a front open combustion chamber, a rear combustion chamber, an air heating chamber between the front and rear combustion chambers, an annular heat radiating flue above and in communication with one of the combustion chambers, the air heating chamber divid ing below the annular radiator and arranged to direct air rising in the air heating chamber through separate courses, one course extending centrally through the annular radiator and another course extending outside the radiator, whereby said rising air surrounds at least a part of the radiator, and means for carrying off the gaseous products of combustion from the upwardly extending combustion chamber and the annular radiator.

14. A fuel burner for heating a building comprising, a grate, a front combustion chamber above the grate and normally open for heating the building by direct radiation, a rear combustion chamber for indirectly heating the building by convection, said rear combustion chamber receiving air for combustion through the front combustion chamber, an air heating chamber between the combustion chambers for receiving heat from both combustion chambers to heat the building by convection, whereby said burner is arranged to simultaneously heat the building by direct radiation and convection, means for carrying off the gaseous products of combustion, and means for closing the front combustion chamber to provide two concurrently operating convection heating combustion chambers without direct radiation of heat from the fuel into the building and the relative proportion of combustion air passing through the front combustion chamber with respect to that passing through the rear combustion chamber is diminished.

15. A construction substantially like that set forth in claim 14 in which the closing meansis adjustable to simultaneously regulate the relative amount of heating by direct radiation from the fuel and the relative amounts of combustion air passing through the front and rear combustion chambers.

16. A fuel burner for a building comprising a front open combustion chamber, a rear combustion chamber, a grate under the front combustion chamber for supporting fuel, said grate arranged for combustion air to pass upwardly through the grate into the front combustion chamber, a fuel pan beneath the rear combustion chamber for supporting fuel, and means for regulating the effective fuel supporting area of the grate with respect to the effective fuel supporting area of the pan.

17. A fuel burner for a building comprising a front open combustion chamber, a rear combustion chamber, a grate under the front combustion chamber for supporting fuel, said grate ar ranged for combustion air to pass upwardly through the grate into the front combustion chamber, a fuel pan beneath the rear combustion chamber for supporting fuel, and the grate slidably supported for movement toward and away from the pan for regulating the relative fuel supporting capacity of the grate and the pan.

18. An air conditioner for a building comprising an air chamber, a combustion chamber open being common to the air chamber for heating air circulated through the latter, openings in the upper region of the air chamber through which.

air from the conditioner is circulated in the building, openings into the bottom of the air chamber, said last named openings communicating with a room of the building below that in which the conditioner is located, air cleaners and filters disposed across said openings for conditioning air circulated through the air chamber, and motor driven means for drawing air into the air chamber through the bottom openings and discharging air through the upper openings whereby relatively cool air may be withdrawn from a lower story in a building and conditioned for circulation through an upper story, said air being optionally heated or permitted to remain cool.

19. A fuel burner for heating a building comprising a combustion chamber open to the atmosphere of the building, an air heating chamber partially. surrounding the combustion chamber and having common walls therewith for heating air in the air chamber,- a grate for the combustion chamber to support fuel, an opening in a common wall, a fuel hopper disposed wholly without the combustion chamber and in communication with the combustion chamber through said common wall opening, closure means for the fuel hopper through which fuel may be charged therein, and means for carrying off the gaseous products of combustion from said combustion chamber.

20. A construction substantially like that set forth in claim 19 in which the bottom of the opening from the fuel hopper to the combustion chamber is substantially level with the fuel supporting grate whereby fuel moves without a free drop from the hopper to the grate.

21. A construction substantially like that set forth in claim 19 in which the opening from the fuel hopper to the combustion chamber is substantially encircled by water conducting means for cooling the region of the opening.

22. A construction substantially like that set forth in claim 19 in which the fuel hopper communicates through a passage with the means for carrying off combustion products whereby gases in the hopper are withdrawn through said passage and the hopper ventilated.

23. A construction substantially like that set forth in claim 19 in which the fuel hopper and means for carrying off combustion products are in communication through a passage and a door is arranged to shut the passage when the charging means is closed and to open the passage when the charging means is open.

24. A construction substantially like that set forth in claim 19 in which the opening from the fuel hopper to the combustion chamber is provided with a vertically sliding door normally tending to move by gravity to close the opening.

25. A construction substantially like that set forth in claim 19 in which the grate has openings through the bottom for the passage of combustion air, a fuel pan without bottom openings disposed in the combustion chamber to the rear of the grate and substantially on the samelevel therewith, and the fuel hopper opening communicates with the pan-whereby fuel from the hopper moves over the pan prior to burning on the grate.

26. A fuel burner for heating a building, comprising a grate, a front open combustion chamber, a rear combustion chamber. an air heating chamber between the front and rear combustion chambers, an annular heat radiating flue above and in communication with one of the combustion chambers through an opening in the flue, said flue being inclined upwardly from said opening whereby hot gases have a generally ascending path through the flue, and a common outlet flue for carrying of! the gaseous products of combustion from the other of said combustion chambers and the annular flue.

27. A fuel burner for heating a building, com prising a grate, a front combustion chamber above the grate and open on one side to the atmosphere of a. room in the building for direct radiation of heat into the room from the combustion chamber, a rear combustion chamber, an air heating chamber around the rear combustion chamber and a portion of the front combustion chamber, said air heating chamber being in heat exchanging relation with both combustion chambers and having common walls therewith, anopening in one of said walls, a fuel hopper disposed wholly without the combustion chamber and in communication with the combustion chamber through said opening, closure means for the fuel hopper through which fuel may be charged therein, and means for carrying off the gaseous products of combustion from said combustion chamber.

28. A fuel burner for heating a building, comprising a grate, a front combustion chamber above the grate and open on one side to the atmosphere of a room in the building for direct radiation into the room from the combustion chamber, a rear combustion chamber, an air heating chamber around the rear combustion chamber and a portion of the front combustion chamber, said heating chamber being in heat exchanging relation with both combustion chambers, and means extending through the air heating chamber and opening into a combustion chamber above the grate through which means solid fuel may be passed to the grate whereby the burner may be fired without introducing the fuel through the heat radiating opening of the front combustion chamber.

29. A fuel burner for heating a building, comprising a grate, a front combustion chamber above the grate and open on one side to the atmosphere of a room in the building for direct radiation into the room from the combustion chamber, a rear combustion chamber, an air heating chamber around the rear combustion chamber and a portion of the front combustion chamber, said air heating chamber being in heat exchanging relation with both combustion chambers and including a hollow partition interposed between the front and rear combustion chambers, said partition having heat conducting walls for absorption of heat from both combustion chambers, and means extending through the air heating chamber and opening into the rear combustion chamber for passing solid fuel to the grate whereby the burner may be fired without introducing the fuel through the heat radiating opening of the front combustion chamber.

30. A fuel burner for heating a building, comprising a grate, a front open combustion chamber, a rear combustion chamber, an annular heat radiating flue above and in communication with one of the combustion chambers, and a common outlet flue for carrying on the gaseous products of combustion from the other of said combustion chambers and the annular flue.

31. In a fuel burner for heating a building, a. combustion chamber open on one side to the atmosphere of a room in the building for the direct radiation of heat into the room from the combustion chamber, a grate of foraminous character through. which air can pass upwardly to fuel burning thereon, and a fuel pan of imperforate character through which air cannot pass to fuel supported thereon, said grate and pan being disposed at the bottom of the combustion chamber for supporting solid fuel, the pan and grate being on substantially the same level whereby fuel can be pushed from one to the other, an ash receiver beneath the grate, and means for carrying off the products of combustion from the combustion chamber.

32. In a fuel burner for heating a building, a combustion chamber open on one side to the atmosphere of a room in the building for the direct radiation of heat into the room from the combustion chamber, a grate of foraminous character at the bottom of the combustion chamber for supporting partially consumed solid fuel, said grate having openings through which air can pass upwardly to fuel burning thereon and said grate being at the front of the burner and having one edge along the bottom of the heat radiating opening, a fuel pan of imperforate character through which air cannot pass to fuel supported thereon, said pan being disposed at the rear of the grate and substantially on the same level therewith to support freshly charged solid fuel in the rear of the combustion chamber whereby solid fuel may be initially charged onto the pan and after a preliminary period of combustion being progressively moved forward from the pan to the grate, an ash receiver beneath the grate, and means for carrying off the products of combustion from the combustion chamber.

33. In fuel burner for heating a building, a combustion chamber open on one side to the atmosphere of a room in the building for the direct radiation of heat into the room from the combustion chamber, a grate of foraminous character through which air can pass upwardly to fuel burning thereon, and a fuel pan of imperforate character through which air cannot pass to fuel supported thereon, said grate and pan being dispeed at the bottom of the combustion chamber for supporting solid fuel, the pan and grate being on substantially the same level whereby fuel can be pushed from one to the other, means for regulating the effective fuel supporting area of the grate with respect to the effective fuel supporting area of the pan.

34. In a fuel burner for heating a building, a combustion chamber open on one side to the atmosphere of a room in the building for the direct radiation of heat into the room from the combustion chamber, a grate of foraminous character through which air can pass upwardly to fuel burning thereon, and a fuel pan of imperforate character through which air cannot pass to fuel supported thereon, said grate and pan disposed at the bottom of the combustion chamber for supporting solid fuel, the pan and grate being on substantially the same level whereby fuel can be pushed from one to the other, a fuel hopper disposed wholly without the combustion chamber and in communication with the combustion chamber above the fuel pan whereby fuel charged into the hopper is received in the combustion chamber first by the imperforate pan and may be then advanced from the pan to the grate, closure means for the fuel hopper through which fuel may be charged thereinto, an ash receiver beneath the grate, and means for carrying off the products of combustion from the combustion chamber.

35. A fuel burner for heating a building, comprising a combustion chamber open to the atmosphere of the building, an air heating chamber partially surrounding said combustion chamber and having common walls therewith, a plurality of air directing plate members disposed in the air heating chamber in generally spaced relation to said common walls to be heated by radiation therefrom, each of said plates being individually of materially less area than the common wall from which it is spaced and arranged to permit the free access of air around the edges thereof into the space between the plate and the common wall, whereby air moving through the air heating chamber around the plate members sweeps over the opposed heated surfaces of the combustion chamber Walls and the air directing members.

36. A fuel burner for heating a building, comprising a combustion chamber open to the atmosphere of the building, an air heating chamber partially surrounding said combustion chamber and having common walls therewith, a plurality of air directing plate members disposed in the air heating chamber in generally spaced relation to said common walls to be heated by radiation therefrom, each of said plates being individually of materially less area than the common wall from which it is spaced and arranged to permit the free access of air around the edges thereof into the space between the plate and the common wall, the top and bottom marginal edges of said air directing members being substantially parallel to and spaced from the combustion chamber walls whereby air in the air heating chamber moves through the spaces between the air directing plate members and the combustion chamber walls in a generally ascending direction upon being heated by the combustion chamber walls and air directing members.

37. A fuel burner for heating a building, comprising a combustion chamber open to the atmosphere of the building, an air heating chamber partially surrounding said combustion chamber and having common walls therewith, a plurality of air directing plate members disposed in the air heating chamber in generally spaced relation to said common walls to be heated by radiation therefrom, each of said plates being individually of materially less area than the common wall from which it is spaced and arranged to permit the free access of air around the edges thereof into the space between the plate and the common wall, all of the marginal edges of said platemembers being spaced from the common walls and the upper marginal edges being closer to the common walls than the other marginal edges whereby the tops of the plate members are inclined toward the common walls to direct air moving upwardly in the air heating chamber against the relatively hot combustion chamber walls.

38. A fuel burner fOl heating a building, comprising a grate, a combustion chamber above the grate and open on one side to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, said chamber having heat conducting walls, an air heating chamber in heat exchanging relation with the Walls of the combustion chamber, inlet and outlet openings for admitting air to the air heating chamber and discharging the same for circulation in the building, an annular heat radiating flue above the combustion chamber and in communication therewith, and an outlet flue for carrying off the products of combustion.

39. A fuel burner for heating a building, comprising a grate, a combustion chamber above the grate and open on one side to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, said chamber having heat conducting walls, an air heating chamber in heat exchanging relation with the walls of the combustion chamber, inlet and outlet openings for admitting air to the air heating chamber and discharging the same for circulation in the building, an annular heat radiating flue above the combustion chamber and in communication therewith, said air heating chamber extending upwardly about the heat radiating flue, an air passageway in said air heating chamber substantially embraced by said flue whereby one portion of the air flowing through the air heating chamber moves upwardly around the annular flue and another portion of the air is substantially surrounded by the said heat radiating flue, and an outlet flue for carrying ofi the products of combustion.

40. A fuel burner for heating a building, comprising a grate, a front open combustion chamber, a rear combustion chamber, an annular heat radiating flue in communication with one of the combustion chambers through an opening, said flue being inclined upwardly from said opening, and a common outlet flue for carrying 011 the gaseous products of combustion from the other of said combustion chambers and the annular flue.

41. A fuel burner for heating a building, comprising a grate, a combustion chamber above the grate and open on one side to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, an ash pit beneath the grate, an ash can in the pit to receive ashes and the like from the grate, an opening into the ash pit other than on the same side thereof as that on which the combustion chamber is open, said ash pit opening being of larger dimension than the ash pan to permit the ash pan to be removed from the ash pit and replaced therein through said ash pit opening, and closure means for the said ash pit opening.

42. A fuel burner for heating a building, comprising a casing, a combustion chamber in the casing, an opening through one side thereof to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, a grate in the combustion chamber for supporting solid fuel, an ash pit beneath the grate, an ash pan in the pit to receive ashes and the like from the grate, an opening through the casing into the ash pit on the opposite side of the casing from the combustion chamber opening, said ash pit opening being of larger dimension than the ash pan to permit the ash pan to be removed from the ash pit and replaced therein through said ash pit opening, and closure means for the said ash pit opening.

43. A fuel burner for heating a building, comprising a casing, a front combustion chamber in the casing opening through the wall in the casing to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, a rear combustion chamber on the opposite side of the front combustion chamber from said opening, an air heating chamber between the walls of the casing and the combustion chambers, inlet and outlet openings for admitting air to and discharging air from the air heating chamber, a common outlet flue for carrying off the gaseous products of combustion from both combustion chambers, said outlet flue being disposed horizontally in the air heating chamber and extending from one of the combustion chambers over the other combustion chamber and through the casing.

44. A fuel burner for heating a building, comprising a casing, a. front combustion chamber in the casing opening through a wall in the casing to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, a rear combustion chamber on the opposite side of the front combustion chamber from said opening, a main air heating chamber between the walls of the casing and the combustion chambers, inlet and outlet openings for admitting air to and discharging air from the air heating chamber, a secondary air heating chamber between the front and rear combustion chambers and continuous with the main air heating chamber, motor driven means for forcing air to be heated through the air heating chambers, said air forcing means located wholly Without said secondary air heating chamber, and means in the main air heating chamber against which the forced air impinges for directing said forced air to flow from the main heating chamber through the secondary air heating chamber.

45. A fuel burner for heating a building, com prising a combustion chamber open on one side to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, an annular heat radiating flue disposed above the chamber and in communication therewith, an outlet flue in communication with the annular flue for carrying ofi the products of combustion, an air heating chamber substantially surrounding the annular flue and in heat exchanging relation with the walls thereof, an inlet opening for admitting air to the heating chamber, and an outlet opening through which heated air is discharged from the air heating chamber for circulation in the building.

46. A fuel burner for heating a building, comprising a combustion chamber open on one side to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, an annular heat radiating flue disposed above the chamber and in communication therewith, an outlet flue in communication with the annular flue for carrying off the products of combustion, an air heating chamber substantially surrounding the annular flue and in heat exchanging relation with the walls thereof, said air heating chamber extending upwardly about the outside of the annular flue and including a central air passageway substantially embraced by the annular flue whereby one portion of the air flowing through the air heating chamber moves upwardly around the outside of the annular flue and another portion of the air is substantially surrounded by the annular flue, an inlet opening for admitting air to the heating chamber, and an outlet opening through which heated air is discharged from the air heating chamber for circulation in the building.

4'7. A fuel burner for heating a building, comprising a casing, a combustion chamber in the casing having an opening through one wall of the casing to the atmosphere of a room in the building for direct radiation of heat into the room from the combustion chamber, an air heating chamber between the walls of the casing and the combustion chamber, an inlet opening for admitting air to the air heating chamber, an outlet opening for discharging air from the air heating chamber, an annular heat radiating flue disposed in the air heating chamber and communicating with the combustion chamber to receive hot'gases therefrom, and a horizontally disposed outlet flue, having heat conducting walls, for carrying off the gaseous products of combustion, said outlet flue extending through the air heating chamber adjacent the top thereof in a substantially straight line and below the level of the outlet opening whereby air in the air heating chamber sweeps over the walls of the outlet flue before being discharged from the outlet opening.

48. An air conditioner for a building comprising an air chamber, a combustion chamber open to the atmosphere of a first room of the building, the major portion of the walls of the combustion chamber being common to the air chamber and of heat conducting material, an outlet flue extending through the air chamber for carrying off the gaseous products of combustion from the combustion chamber, an outlet opening adjacent the top of the air chamber through which air may be discharged therefrom for circulation in the building, an inlet opening into the bottom of the air chamber, said inlet opening communicating with a second room of the building below said first room in which the air and combustion chambers are located, an air cleaning filter disposed across one of the openings and humidifying means for conditioning air circulated through the air chamber, and motor driven means for moving air into the air chamber through the inlet opening from said lower second room and discharging conditioned air into said first room through the outlet opening.

49. A construction substantially like that set forth in claim 27 in which the bottom of the opening from the fuel hopper to the combustion chamber is substantially level with the fuel supporting grate whereby fuel moves without a free drop from the hopper to the grate.

50. A construction substantially like that set forth in claim 27 in which the opening from the fuel hopper to the combustion chamber is substantially encircled by water conducting means for cooling the region of the opening.

51. A construction substantially like that set forth in claim 27 in which the fuel hopper communicates through a passage with the means for carrying off combustion products whereby gases in the hopper are withdrawn through said passage and the hopper ventilated.

52. A construction substantially like that set forth in claim 27 in which the fuel hopper and means for carrying off combustion products are in communication through a passage and a door is arranged to shut the passage when the charging means is closed and to open the passage when the charging means is open.

53. A construction substantially like that set forth in claim 27 in which the opening from the fuel hopper to the combustion chamber is provided with a vertically sliding door normally tending to move by gravity to close the opening.

forth in claim 27 in which the grate has openings through the bottom for the passage of combustion air, a fuel pan without bottom openings disposed in the combustion chamber to the rear 35 30 54. A construction substantially like that set 

